The present invention relates to an optical disk drive, also referred to herein as simply a disk drive, for recording a data signal and/or reproducing a data signal recorded to an optical disk, also referred to herein as simply a disc, used as a data storage medium. A Compact Disc or CD is exemplary of such data storage media.
A disk drive typical of those related to the present invention has an opening on the front panel through which a disk tray opens and closes. After the tray is opened and a disk is loaded onto the tray, the tray is automatically closed, that is, retracted into the disk drive to a turntable.
When a disk is loaded into this type of disk drive it is held between the turntable and a clamp and driven at a specific rotational speed so that data signals recorded to the disk can be read by the disk drive, that is recording or reproducing apparatus, during a read operation, for example. More specifically, signals are recorded to tracks within a specific area of the disk, and an optical pickup for signal reading is driven according to the track address of the desired signal so that the desired signal can be reproduced.
This type of disk drive has three basic operations that require drive motor power: (1) disk loading whereby the tray is driven in two directions between a disk loading/unloading position outside the disk drive at which a disk can be placed on or removed from the tray, and a loading/unloading position inside the disk drive at which the disk is loaded to or unloaded from the turntable; (2) disk driving whereby the turntable is driven to spin a disk; and (3) pickup driving whereby an optical pickup is driven primarily between positions at the outside circumference and inside circumference of the disk.
Typical disk drives according to the related art have also used separate motors, that is, three individual motors, as the drive source for these three operations.
This problem of needing three motors was partially addressed by a disk player (disk drive) as taught in Japanese Utility Model Laid-Open Publication No. 3-49682. This disk player reduced the number of required motors to two, that is, driving a single loading motor in forward and reverse directions for disk loading and unloading, disk chucking, and pickup drive.
A disk drive according to the related art typically comprises a case and a chassis essentially integrated with the case, a turntable fixed to the chassis, and the drive motors. That is, because the vertical position of the turntable is fixed, the disk must be moved vertically for disk loading and unloading in order to avoid interference with the turntable. In addition, the clamping means (chucking plate) must be driven vertically in order to clamp the disk to the turntable.
A disk holder for lifting the disk is therefore provided at the disk holding surface of the tray in a conventional disk drive. The disk holder is then rotated up or down timed to the tray movement so as to avoid interference between the disk and turntable during disk loading and unloading. A chucking plate is further provided supported by a chucking arm on the fixed chassis so that the chucking plate can rotate and move vertically. This chucking plate is rotated up or down according to the disk loading and unloading timing to either clamp the disk to the turntable or to release the disk. Drive construction and operating the component parts are thus quite complicated and disadvantageous with respect to simplifying drive construction and achieving good stable operation.
Furthermore, all drive parts other than the tray and associated drive system are also provided on the fixed chassis in this conventional disk drive. In addition, these parts are rigidly attached or supported on the fixed chassis. As a result, any impact, shock, or vibration to which the disk player is exposed is also transmitted directly from the fixed chassis to the various rigidly attached drive parts. These parts are thus easily susceptible to major damage. This design is therefore disadvantageous with respect to improving the durability of the disk drive to the effects of external forces, that is, resistance to shock and vibration.
Rigid attachment of these components to the fixed chassis also makes it necessary to extremely precisely position these components relative to each other. Extremely high precision is therefore required in both parts manufacture and assembly. When the need to mass produce these components is considered, this need for extremely high precision is disadvantageous with respect to increasing productivity.
Considering these problems of the related art, the basic object of the present invention is therefore to provide an optical disk drive whereby the number of motors used can be reduced, construction can be simplified, durability and resistance to shock and vibration can be improved, and productivity can be improved in mass production.
To achieve this object, an optical disk drive according to a first aspect of the present invention has a turntable for rotatably supporting an optical disc, an optical pickup for writing a data signal to an optical disc rotating on the turntable or reading a data signal recorded to the optical disc, a pickup drive mechanism for moving the optical pickup bidirectionally between the inside circumference side and outside circumference side of the optical disc, and a disk loading mechanism for moving an optical disc bidirectionally between a first position at which the optical disc is above the turntable, and a second position at which the optical disc is outside the disk drive, a first base comprising a base frame of the disk drive, and a second base separate from the first base. The second base is supported to move or swing vertically relative to the first base, and has connected thereto the turntable and a first motor for rotationally driving the turntable, and the optical pickup and pickup drive mechanism. On the first and/or second base are: a loading drive mechanism for driving said disk loading mechanism; a second motor that can be driven in forward and reverse directions for supplying drive power to the loading drive mechanism and pickup drive mechanism; and a drive power transfer path switching mechanism for switching the drive power transfer path of the second motor between a path transferring power to the loading drive mechanism and a path transferring power to the pickup drive mechanism. Thus comprised, moving the optical pickup, raising or lowering the turntable, and moving the optical disc can be substantially continuously performed in this sequence by driving the second motor continuously in a first direction of rotation. These operations can be performed in reverse direction in reverse sequence substantially continuously by driving the second motor continuously in reverse of this first direction of rotation.
A separate second base is thus supported on a first base such that the second base can move or swing in a circular path vertically relative to the first base. A single motor (the above-noted second motor) can also be driven continuously forward (in a first direction of rotation) or in the opposite direction to move the optical pickup, raise or lower the turntable, and move the optical disc substantially continuously in this sequence, or substantially continuously in reverse direction in reverse sequence.
In an optical disk drive according to a second aspect of the present invention, the second base is disposed inside an opening in the first base, and is supported so that it can swing vertically pivoting around one end thereof relative to the first base. The first base comprises thereon a cam gear disposed near the other end side of the second base, and the cam gear has on an outside surface thereof a cam channel for raising and lowering the other end of the second base. The loading drive mechanism has a loading drive gear set containing a plurality of gears including a final output gear. The final output gear of the loading drive gear set engages an outside teeth part of the cam gear to rotate the cam gear and thereby raise or lower the other side of the second base.
In an optical disk drive according to this aspect, the cam gear is rotated by drive power transferred from the loading drive gear set, and the other end side of the second base is raised or lowered in conjunction with cam gear rotation. As a result, the second base is swung up or down to the first base pivoting around the one end side of the second base.
In an optical disk drive according to a third aspect of the present invention, the profile of the outside gear part of the cam gear as seen in longitudinal section is an arc or a line approaching the arc. This arc follows a path of vertical circular motion through which the final output gear of the loading drive gear set travels in conjunction with the swinging movement of the second base.
In this case the final output gear of the loading drive gear set positively engages the outside gear part of the cam gear when the final output gear swings up or down in conjunction with the swinging movement of the second base.
In an optical disk drive according to a fourth aspect of the present invention, a protrusion is arranged at the other end side of the second base, and this other end side of the second base is positioned vertically as a result of this protrusion engaging a cam channel in the cam gear.
In this optical disk drive, vertical positioning of the other end side of the second base to the first base is reliably determined by engagement of the protrusion and cam channel.
In an optical disk drive according to a fifth aspect of the present invention, the disk loading mechanism comprises a tray drive gear for driving the tray on which a disk is placed. When the second base swings downward to a specific position relative to the first base, the outside gear part of the cam gear engages the tray drive gear.
In this optical disk drive, the tray is driven after the second base has positively swung down from the first base.
In an optical disk drive according to a sixth aspect of the present invention, the pickup drive mechanism comprises a feed rack for moving the optical pickup, and a rack drive gear set comprising a plurality of gears for driving the feed rack.
After moving the optical pickup to an inside circumference edge position of the data signal recording area of the optical disc, the feed rack can be moved to a specific position farther to the inside circumference side of the disc. By moving to this specific position at the inside circumference side and engaging the drive power transfer path switching mechanism, the second motor drive power transfer path is switched from a path to the pickup drive mechanism to a path transferring power to the loading drive mechanism. By moving from the specific position at the inside circumference side to the outside circumference side of the disc and thereby disengaging from the drive power transfer path switching mechanism, the second motor drive power transfer path is switched from a path transferring power to the loading drive mechanism to a path transferring power to the pickup drive mechanism.
In this optical disk drive the drive power transfer path of the second motor can be automatically switched as a result of the feed rack moving to this specific position to the inside circumference side of the disk after moving the optical pickup to an inside circumference edge of the data signal recording area of the optical disc, and again when the feed rack moves from this specific position toward the outside circumference side of the disk.
In an optical disk drive according to a seventh aspect of the present invention, a regulating rod retractable from the other end side is arranged at the second base, and a positioning channel that can be engaged by this regulating rod is arranged in the first base. The feed rack engages the regulating rod when it moves from the one end side to the other end side of the second base and reaches a specific position. The regulating rod protrudes from the other end side of the second base and fits into the positioning channel when the feed rack moves further toward the other end side after engaging the regulating rod, thereby positioning the second base to the first base in a lateral direction perpendicular to the direction of feed rack travel.
In this optical disk drive, the regulating rod is driven to project from the other end side of the second base as a result of the feed rack moving beyond a specific position to the other end side. The regulating rod thus fits into the positioning channel in the first base, and thereby determines the lateral position of the second base to the first base perpendicular to the direction of feed rack travel.
In an optical disk drive according to an eighth aspect of the present invention, the cam gear comprises a hook part projecting to the outside, and the second base comprises on a surface thereof a curved channel parallel to an outside part of the cam gear. The hook part engages this curved channel to position the second base at the first base in the direction of feed rack travel.
As a result of the cam gear hook part engaging this curved channel, the second base is positioned at the first base in the direction of feed rack travel.
In an optical disk drive according to a ninth aspect of the present invention, an elastic damping member is arranged at a support part for supporting the one end side of the second base at the first base, and at a support part for supporting the cam gear to the first base. The second base is thus supported in a floating state on the first base within the range of elasticity of the damping members.
The second base is therefore not rigidly supported on the first base, but is instead supported so as to float on the first base within limits determined by the flexibility of the damping members.
Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings.